1. Technical Field of the Invention
The present invention relates to a network having a powerline backbone and, more particularly, to such as a network that includes wireless communication.
2. Background Art
Electrical powerlines, such as are typically found in homes and businesses, have been used as a medium through which signals may communicate from one electrical device to another over a local area network (LAN). For example, a network of two personal computers may be created as follows. A first computer is interfaced through wires to an outlet of the powerline. A second computer is interfaced through wires to another outlet of the powerline. In the United States, powerline signals typically have a frequency of about 60 Hz. Network signals that have a frequency that is substantially higher than 60 Hz pass between the computers on the powerline. A high pass filter is used to filter out the 60 Hz power signal.
Relatively expensive radio frequency (RF) technology has also been used to connect computers or other electronic devices in the home or business through RF signals, rather than through a powerline. Such technology has included direct sequence spread spectrum and frequency hopping spread spectrum technology and provides relatively high frequency data signals. Such technology may work fairly well over a hundred foot or more radius and the signals associated therewith can reliably pass through typical walls. This RF technology has the advantage of allowing electronic devices to be untethered to a wall. However, typically, the RF base station is connected at or very close to the electronic device, such as a computer, which may not be optimally positioned for reliable data signal transmission or reception. Further, this technology is prohibitively expensive for many consumers and businesses.
Significantly less expensive RF technology has been used to allow electronic devices to communicate through RF signals. Such technology has much smaller transmission and reception areas and cannot reliably pass signals through walls. Further, the RF base station is typically connected at or very close to the electrical device which may not be optimally positioned for reliable data signal transmission or reception, further reducing transmission and reception area. The area of reception may be so small as to not completely cover many houses. Because of the small area of transmission and reception and lack of reliability, such technology is unsatisfactory for many applications.
Accordingly, there is a need for a network wherein untethered electrical devices may communicate with other devices in the network through relatively inexpensive equipment.